In recent years, much effort has been devoted to the total synthesis of steroids. The medicinally important 19-norsteroids have been the subject of a large number of chemical investigations, cf. D. Djerassi, Science, 151, 1055 (1966); L. Velluz et al., Tetrahedron Supplement 8, Part II, 495 (1966). 19-Norsteroids have been prepared in accordance with prior art teachings by the reduction of Ring A aromatic steroids either chemically [A. L. Wilds et al., J. Am. Chem. Soc. 75, 5366 (1953)] or photolytically [J. A. Waters et al., J. Am. Chem. Soc. 89, 1022 (1967)]. Other methods known in the art for the preparation of 19-norsteroids include oxidation of the C-19 methyl group of a steroid to the corresponding carboxylic acid followed by acidic decarboxylation of the resulting 19-carboxy-.DELTA..sup.4 -3-keto system. [A. Bowers et al., J. Am. Chem. Soc. 84, 3204 (1962)].
The present invention relates to certain polycyclic compounds and processes for their synthesis. The novel intermediates and processes of this invention provide a new synthetic route for the preparation of pharmaceutically valuable 19-nor-steroids. Further, the intermediates and processes of the invention provide a novel route for the preparation of pharmaceutically valuable estrones. In synthesis of steroidal materials, steric considerations are of great significance. The most used steroidal compounds are those having a C/D-trans-ring junction with the substituent in the 13-position being in the .beta.-configuration. The present invention provides a facile total synthesis of 13.sub..beta. -C/D-trans-steroidal materials. This desirable result is obtained via a unique asymmetric induction followed by subsequent stereospecific reaction steps.